SAN FRANCISCO (NBC) -- An oil tanker struck one of the San Francisco-Oakland Bay Bridge towers late Monday morning, officials said.

The vessel, named the Overseas Reymar, struck the so-called "Echo Tower," or Tower 6, on the far east side of the bridge's western span around 11:20 a.m., according to the Coast Guard.

Caltrans spokesman Bart Ney said the ship damaged its own fender system but there was no damage to the bridge itself. From the NBC Bay Area chopper, there was some visible damage to the base of the bottom floating portion of the concrete base of the bridge.

There were no reports of spilled oil or major injuries.

The vessel is being detained in the Bay while the Coast Guard responds.